Ten years later, we need to take stock about how 9/11 shaped history. We also need to ask where the Free World, particularly the U.S., made the mistakes that amplified the impact of 9/11 beyond what it should have been.

This is not easy, because terror generates overpowering emotion: Fear, rage, humiliation, unbearable loss and the desire for revenge. Politicians are under enormous pressure when it comes to terror, because they need not only to be effective in their actions, but are also required to channel these emotions.

Like most citizens of the Free World, I took 9/11 very personally. I experienced it as an attack not only on the nation that leads the Free World, but also as an attack on the values that are sacred to me: liberty, life and the right to dignity.

My reaction, like that of many Westerners, including George W. Bush, was stormy, emotional – and very unsuited as a guide for fighting the varieties of terrorism.

In the 10 years since, I have had the privilege to work with some of the leading terrorism researchers in the world, such as Scott Atran and Marc Sageman. I have learned a lot from them, and also from other thinkers who have made it their calling to understand the new forms of global terrorism and their implications for the world order – such as constitutional scholar and historian Philip Bobbitt. Here are two of the conclusions to be derived from their work.

A general War on Terror makes no more sense than a general War on Illness.

We all want terror to stop - and we all want illnesses to be vanquished. But anyone who would declare war on illness would be looked at as totally irrational: You can research cancer (actually, many different forms of it), cardiovascular disease, autoimmune diseases, etc. Fighting disease as such is a non-strategy. Each illness must be met on its own ground – and so must each form of terrorism.

What we unify under the name ‘terrorism’ are widely varying phenomena: national liberal movements that turn to political violence are very different from groups like Baader-Meinhoff in the 1970s that have neither territorial demands nor clear political goals.

National liberation movements that want self-definition for a particular group (i.e. ETA for the Basques) but do not deny the legitimacy of the state they want to separate from (Spain, in this case) are akin to, and yet different from, groups like Hamas that not only want political self-determination for a people, but also claim that they want to destroy the state they are fighting (in this case, Israel).

All these, in turn are very different from the very modern phenomenon of Al-Qaida, a group that has no clearly defined political objective, doesn’t represent any particular ethnic group, and is loosely defined by a certain interpretation of religion and a demonization of the West, its power and culture. Its goal is to destabilize a world-order that they deem to be unjust and diabolic: global, Western-led capitalism and secular culture.

The common denominator of these widely differing movements and organizations is but one: they do not try to vanquish their enemies or opponents militarily, as they do not have the means to do so. Their acts of destruction are meant to generate the mental state of terror.

Hence the second conclusion: While terrorism, by its nature, generates fear and rage, it can only be fought successfully with strategies guided by cool analysis and pragmatic thought.

For example, it leads us to enounce principles such as “no negotiations with terrorists”. The peace agreement in Northern Ireland would never have been possible if the British government would have stuck to this doctrine. It engaged with the IRA long before this organization stopped its armed struggle.

Together with Lord John Alderdice, currently chair of the Liberal Democratic Faction in the House of Lords and formerly Chair of the Northern Irish Alliance Party, I have analyzed the analogies between the case of Northern Ireland and Hamas.

The analogies are actually much greater than is often assumed, and hence the question whether Hamas can or should be talked to needs to be answered not on the basis of principles, but of pragmatic calculation. This requires cool-headed analysis of Hamas’ goals, its strategic options, and long-term interests. This may not be easy; particularly when there are many Israeli citizens that have lost loved ones to terror attacks perpetrated by Hamas.

Even dealing with Al Qaeda requires cool-headed analysis. Marc Sageman, a former CIA case-officer has shown in detail that it is wrong to think of Al-Qaida as an integrated, hierarchical organization with a clear line of command. In detailed case studies he has shown how terror cells in Europe came into being without any guidance from the organization’s higher echelons. Al-Qaida is more of a state of mind pulsating through cyberspace than a formal terror organization.

Therefore Leon Panetta’s recent statement that Al-Qaida’s defeat is within reach must be taken with a grain of salt – and I say this with great respect for Panetta’s vast experience. Panetta thinks of victory in military terms – and it may be that indeed many of Al-Qaida’s remaining operational leaders will soon be dead. The problem is that, as Sageman shows, Al-Qaida is a state of mind. Hence the very idea of vanquishing it only by military means is impossible

Scott Atran’s decade-long investigation of global terrorism raises the possibility that global jihadi terrorism will last as long as the state of mind and the existential need for meaning that drives this movement still exists.

Al-Qaida is indeed something like a sickness; it is like a cancerous growth that can metastasize at totally unforeseen places, as the London and Madrid attacks showed. If we don’t understand the dynamics that generates these metastases, they will pop up, again and again.

Hence, to lower the chances for the generation of new terror cells, sophisticated media and community strategies must be applied to influence Islamic minority groups that, are today the major recruiting grounds for global Islamic jihad.

At this point the following objection is often voiced: “You liberals are hopeless; you think we should understand terrorists. They must be apprehended or killed!”

This is a deep misunderstanding. As any chess or poker-player knows, you need to understand your opponent. Not because you want to be nice, but because you want to win.

In fact we will have to learn how to live with terrorism without letting it guide our decision-making and harming liberal democracy.

Constitutional scholar and historian Philip Bobbitt has argued that the new global realities have led to the point where terrorism is there to stay. In its global forms, its goal is to destabilize the Free World. As Bobbit shows with great clarity, the very idea of reaching decisive victories over terrorism is conceptually misguided.

We must no longer think of the battle with terrorism as something that ends with a flag being planted, and a declaration of defeat being issued by the loser. We need to live with it, and we must make sure that liberal democracy is not harmed beyond repair by the demands of the fight against terrorism.

Thinking about the varieties of terrorism levelheadedly, realizing that the phenomenon will not go away, is difficult. But we must, by all means, avoid the result that terrorism aspires to: clouding our minds with fear and rage.

If we will not keep our cool in dealing with the new varieties of terrorism, we will play into its hands and, unwillingly, help terrorists achieve their goal of undermining the liberties that we fight for.

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